The amendment aims to end ongoing legal ambiguities by affirming and strengthening the principles behind the Non-Detention Act of 1971.

"The indefinite detention of a U.S. citizen without due process is fundamentally un-American. Our founding fathers believed so firmly in the right to trial by jury that they enshrined it in the body of the Constitution, and again in the Sixth Amendment,” Sen. Paul said. "We can and will vigorously investigate and prosecute all who seek to do us harm, and we can do so while respecting the constitutional liberties of American citizens.”

“America should never waiver in vigilantly pursuing those who would commit, or plot to commit, acts of treason against our country. But the federal government should not be allowed to indefinitely imprison any American on the mere accusation of treason without affording them the due process guaranteed by our Constitution,” Sen. Mike Lee said. “By forbidding the government from detaining Americans without trial absent explicit congressional approval, the Due Process Guarantee amendment strikes the right balance between protecting our security and the civil liberties of each citizen.”

“Detaining Americans captured within the United States indefinitely without trial or even charge is a clear violation of our Constitution and our values, and it must not be permitted,” said Sen. Feinstein. "We’ve seen over and over again that our criminal justice system is well-equipped to interrogate and convict terrorists, and I support that process. We need to stand strong against terrorism, and we need to do so within the bounds of U.S. law. This amendment has been approved by the Senate in the past but not enacted; I’m hopeful that this year it will be adopted by both chambers of Congress.”

“This bipartisan amendment strengthens our nation’s founding principles of justice and fairness under the law by protecting all American citizens and lawful residents from indefinite detention without charge or trial while also guaranteeing due process of law,” said Sen. Collins. “Despite successfully passing the Senate with sixty-seven votes in 2012, this amendment unfortunately failed to be adopted. I am hopeful that my colleagues on both sides of the aisle will take action to swiftly pass this amendment into law.”

"The Constitution does not allow President Obama, or any President, to apprehend an American citizen, arrested on U.S. soil, and detain these citizens indefinitely without a trial,” said Sen. Cruz. “That’s why I have consistently supported measures to prohibit indefinite detention in the NDAA. The Due Process Guarantee amendment will prohibit the President’s ability to indefinitely detain U.S. citizens arrested on American soil without trial or due process. While we must vigorously protect national security by pursuing violent terrorists and preventing acts of terror, we must also ensure our most basic rights as American citizens are protected.”

In recent years, some have argued that the indefinite detention of Americans is permissible under the 2001 Authorization for the Use of Military Force (AUMF). The Due Process Guarantee amendment clarifies that the AUMF and other general authorizations cannot be construed as acts of Congress that permit indefinite detention and codifies the “clear statement rule” to clarify that indefinite detention can only occur if Congress expressly authorizes it.

The bill also expands the Non-Detention Act of 1971 to include legal permanent residents in addition to citizens.

In December 2012, the Senate passed this amendment to the fiscal year 2013 National Defense Authorization Act with 67 votes, but it stalled in the House of Representatives. This legislation is almost identical to that language.